Experimental and Numerical Investigation of Single-Phase Forced Convection in Flat Plate Heat Exchanger with Different N
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RESEARCH ARTICLE-MECHANICAL ENGINEERING
Experimental and Numerical Investigation of Single-Phase Forced Convection in Flat Plate Heat Exchanger with Different Numbers of Passes Abdulmajeed Almaneea1 Received: 1 May 2020 / Accepted: 19 August 2020 © King Fahd University of Petroleum & Minerals 2020
Abstract Much of the present and future technology will be based on electronic devices that are operated using an electronic clip. Due to the continuous operation of the majority of electronic devices, the efficiency of such devices decreases because of inefficient cooling techniques. Therefore, the present study experimentally and numerically investigates the thermal resistance and friction factor for the flat plate heat exchanger in the range of Reynolds number 7500–38,000. The study also examines the effect of the number of passes on the thermal performance of a flat plate heat exchanger. Based on the experimental and numerical results of a 4-pass flat plate heat exchanger, the empirical correlation for the thermal resistance and friction factor is suggested to be within the error range of ± 3.5% and ± 5%, respectively. For the optimum performance of the flat plate heat exchanger, the thermal resistance and friction factor should be as low as possible. The numerical results show that the thermal resistance decreases, and the friction factor increases with the number of passes in the flat plate heat exchanger; therefore, out of 2, 4, and 6 passes, the study suggests that 4 passes provide a compromising option for thermal resistance as well as the friction factor. Keywords Plate heat exchanger · Thermal resistance · Reynolds number · Friction factor
List of symbols Q˙ ν d L f q U uT 2 Re ρ T P Rs
B 1
Flow rate of water Kinematic viscosity Tube inner diameter Tube length Friction factor Heat flux Unfiltered velocity Average velocity transport Turbulent dissipation rate Reynolds number Working fluid density Temperature Pressure difference Thermal resistance Abdulmajeed Almaneea [email protected] Department of Mechanical and Industrial Engineering, College of Engineering, Majmaah University, Al-Majmaah 11952, Saudi Arabia
u u μ σ
Average velocity vector Velocity fluctuations vector Viscosity Prandtl number
Subscripts i w s T
Inlet Water Surface Turbulent
1 Introduction In current scenario, almost all devices from basic needs to advance research equipment such as controllers, magnetic resonance imaging (MRI) machines, radio-frequency (RF) generators, battery chargers, UPS, traction devices for locomotives, AC–DC inverters and DC–AC converters are controlled by electronic circuits, and this had led to a con-
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Arabian Journal for Science and Engineering
tinuous increase in the demand for electronic devices. With regard to such devices, some are operated for a few seconds, whereas the majority fall into in the category of continuous operation, even over a number of years. The major factor in the failure of such devices which are in continuous operation is the low thermal resistance. This is because with in
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